The present invention relates generally to an ortho mode transducer (OMT)/multiplexer assembly and, more particularly, to an OMT/multiplexer assembly having a corrugated junction.
Typical OMTs are not associated with multiplexing devices or filtering devices. In fact, typical OMTs are limited to a single frequency band. Satellites, however, often have two different frequency bands: an uplink frequency (upper) band and a downlink frequency (lower) band. Until recently, satellites did not routinely require two polarizations for both frequency bands. However, dual polarization transmit/receive subsystems are becoming common in communications and radiometric satellites. With two polarization modes being associated with each band, there is a need for a device which diplexes and ortho mode transduces a plurality of frequency bands.
Conventional signal extraction devices for extracting more than two transmit/receive bands are massive and extract signals in a cumbersome manner using corrugated lowpass filters that are side coupled to square waveguides. There is a need for a device that is compact in a radial dimension and provides improved interband isolation.
Fabrication of conventional OMTs having corrugated lowpass filters often requires costly electroforming. There is a need for a device which can be fabricated by less complex and less costly means such as machining.
Typical OMTs do not have significant filtering capability, and therefore require the employment of relatively expensive components and other units in the system in order to filter downstream in the signal path. There is a need for a device which provides ortho mode transducing and auxiliary filtering so that the specifications of other units in the system can be relaxed.
Thus, there is a need for a single device which can extract both polarizations of multiple transmit and receive bands while providing filtering and isolation between them.